ES2348115T3 - FOAM COAT BASED ON A BIODEGRADABLE POLYESTER MIX. - Google Patents

Abstract

The invention relates to a foam ply based on a biodegradable polyester mixture, comprising i) from 70 to 5% by weight, based on the total weight of components i to ii, of at least one polyester based on aliphatic and aromatic dicarboxylic acids and on aliphatic dihydroxy compounds, and ii) from 30 to 95% by weight, based on the total weight of components i to ii, of poly-lactide, and iii) from 0.1 to 5% by weight, based on the total weight of components i to ii, of a copolymer which comprises epoxy groups and is based on styrene, acrylates, and/or methacrylates, and iv) from 0.5 to 15% by weight of additives; and v) from 0 to 50% by weight of inorganic or organic filler, and also to processes for production of the foam ply mentioned, and to the use of the foam plies for the production of moldings and foils, and also to moldings and foils comprising the foam plies mentioned.

Description

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Foam layer based on a polyester blend biodegradable.

The present invention relates to layers of foam based on a biodegradable polyester blend, which understands

i)

70 to 5% by weight, based on the total weight of the components i to ii, of at least one acid-based polyester aliphatic and aromatic dicarboxylic and a composition aliphatic dihydroxy;

ii)

30 to 95% by weight, based on the total weight of the components i to ii, of polylactide (PLA), and;

iii)

0.1 to 5% by weight, based on the total weight of the components i to ii, of a copolymer, with group content epoxides, based on styrene, acrylates and / or methacrylates; Y

iv)

0.5 to 3% by weight based on the total weight of the components i) to ii), of a nucleating agent, and

v)

0 - 50% organic fillers or inorganic

In addition, the present invention relates to methods for preparing the aforementioned foam layers and the use of foam layers for the production of molded parts, sheets, as well as molded parts, sheets containing the layers named foam.

Polyester blends have already been described biodegradable with similar composition of components i) up to v) in WO 2006/074815. However, the production of foam layers It hasn't been mentioned there.

JP 2004-067894 describes mixtures polystyrene based on polylactide and polyesters biodegradable aliphatic / aromatic. The crosslinking agent is used a mixture of low molecular weight acrylates and particularly peroxides Although the authors mention that mixtures of Polyesters can foam, no foam layers are produced. Neither chemical and physical properties of the foam are described.

JP 2005-179537 discloses mixtures of polyesters with a high content of polylactide and polyesters aliphatic / aromatic based polyethylene terephthalate, the which can only biodegrade slowly. TO mixtures are not added crosslinkers or compatibilizers before of foaming. Foam layers are not described.

In WO 99/065977 foam sheets are produced a base of aliphatic / aromatic biodegradable polyesters and acetate of cellulose by means of direct gassing with carbon dioxide. The sheets have a high density of more than 200 to 600 g / l.

The known polyester blends of the state of the technique are conditioned conditioned only for the preparation of foam layers. In particular, so far they have not layers of low density film could be produced, in particular 50 g / l. It would also be desirable to provide foam layers with a high portion (greater than 70%) of closed cells since you are have an isolation behavior better than the foams of open cells. Finally, a goal of the present invention is develop foam layers of biodegradable polymers, preferably of renewable raw materials that can be produced no propellant such as hydrocarbon or fluorinated hydrocarbons. The use of inert propellants, such as nitrogen and, in particular, carbon dioxide, along with the ecological aspects, has advantage that the foam layers produced in this way are allowed for the food products sector.

In this way, the present invention has as underlying task provide biodegradable materials that don't have The above mentioned disadvantages.

Surprisingly it has been found now that polyester blends that comprise

i)

70 to 5% by weight, based on the total weight of the components i to ii, of at least one acid-based polyester aliphatic and aromatic dicarboxylic and dihydroxy compound aliphatic;

ii)

30 to 95% by weight, based on the total weight of the components i to ii, of polylactide (PLA), and;

iii)

0.1 to 5% by weight, based on the total weight of the components i to ii, of a copolymer, which contains groups epoxides, based on styrene, acrylates and / or methacrylates; Y

iv)

0.5 to 3% by weight based on the total weight of the components i) to ii), of a nucleating agent and

v)

0 - 50% of fillers, inorganic or organic, such as polymers of renewable raw materials, by example: starches, cellulose, cereals, polyhydroxyalkanoates or polycaprolactone or aliphatic polyesters, which can be processed with propellant agents such as carbon dioxide or nitrogen in layers of foam with low density and high portion of closed cells. The foam layers according to the invention differ in those of the state of the art especially for the mixtures used in polyester, in particular by the compatibilizer (components iii).

In principle, for the production of mixtures of biodegradable polyester according to the invention as component i consider all polyesters based on dicarboxylic acids aliphatic and aromatic and an aliphatic dishydroxy compound as well called partially aromatic polyesters. Obviously also mixtures of several of these polyesters are suitable as component i.

For partially aromatic polyesters also Polyester derivatives should be understood according to the invention such as polyether esters, polyester amide ester amides of polyethers. Suitable partially aromatic polyesters include linear polyesters that are not elongated chain (WO 92/09654). Partially aromatic polyesters of elongated and / or branched chain. The latter are known from documents named at the beginning, WO 96/15173 until 15176, 21689 up to 21692, 25446, 25448 or WO 98/12242, to which it is made reference expressly. They can also be taken into consideration mixtures of different partially aromatic polyesters. In in particular, partially aromatic polyesters should be understood products like Ecoflex® (BASF Aktiengesellschaft), Eastar® Bio and Origo-Bi (Novamont).

Partially aromatic polyesters particularly preferred include polyesters than as components Essentials contain:

TO)

an acid component of

a1)

30 to 99 mol% of at least one acid cycloaliphatic dicarboxylic acid or its derivatives that form esters or mixtures thereof

a2)

1 to 70 mol% of at least one dicarboxylic acid aromatic or its derivative that forms esters or mixtures of same

quad

Y

a3)

0 to 5 mole% of a compound containing groups sulfonates,

B)

a diol component selected from at least one C2 to C12 alkanol and at least one cycloalkanediol from C 5 to C 10 or mixtures thereof and, if desired in addition, one or more components selected from

C)

a selected component of

c1)

at least one dihydroxy compound, of formula I, which contains ether functions

(I) HO - [(CH 2) n -O] m -H

quad

in which n represents 2, 3 or 4 and m represents a integer from 2 to 250.

c2)

at least one hydroxycarboxylic acid of the formulas IIa or IIb

one

quad

in which p means an integer from 1 to 1500 and r means a number from 1 to 4, and G represents a residue which is selected from the group consisting of phenylene, - (CH 2) q -, where q means a number integer from 1 to 5, -C (R) H- and -C (R) HCH2, where R represents methyl or ethyl

c3)

at least one alkanol (C2 a C 12) - amine or a (C 5 -C 10) cycloalcanol - amine or mixtures thereof

c4)

at least one alkane (C 1 -C 8) - diamine

c5)

at least one 2,2'-bisoxazoline of the general formula III

2

quad

where R1 means a single bond, a group (CH 2) z -alkylene, with z = 2, 3 or 4, or a phenylene group

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c6)

at least one aminocarboxylic acid selected from group consisting of natural amino acids, polyamides, obtainable by polycondensation of a dicarboxylic acid with 4 up to 6 C atoms and a diamine with 4 to 10 C atoms. Compounds of formulas IV a and IV b

3

quad

where s means an integer from 1 to 1500 and t means an integer 1 to 4, and T represents a residue that is selected from the group consisting of phenylene, - (CH 2) u -, where u means an integer of 1 up to 12, -C (R2) H- and -C (R 2) HCH 2, where R 2 represents methyl or ethyl, and polyoxazolines with the periodic unit V

4

quad

wherein R 3 represents hydrogen, alkyl of C 1 -C 6, cycloalkyl of C 5 -C 8, unsubstituted or substituted phenyl up to three times with alkyl groups of C 1 -C 4 or tetrahydrofuryl, or mixtures of c1 until c6

Y

D)

a selected component of

d1)

at least one compound with at least three groups capable of forming esters,

d2)

at least one isocyanate

d3)

at least one divinyl ether

or mixtures of d1) to d3).

The acid component A of the polyesters partially aromatic contains, in a preferred form of realization of 30 to 70, in particular 40 to 60 molar% of A1 and 30 to 70, especially 40 to 60% molar of A2.

As aliphatic acids and derivatives corresponding to the general one can be considered those with 2 up to 10 carbon atoms, preferably 4 to 6 atoms of carbon. They can be both linear and branched. The cycloaliphatic dicarboxylic acids usable within the framework of the present invention are regularly those with 7 to 10 atoms of carbon and especially those with 8 carbon atoms. Although principle can also be used dicarboxylic acids with a greater number of carbon atoms, for example with up to 30 atoms carbon

As an example they can be named: acid malonic acid, succinic acid, glutaric acid, acid 2-methylglutaric acid 3-methylglutaric, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, acid 2,2-dimethylglutaric, subic acid, acid 1,3-cyclopentandicarboxylic acid 1,4-cyclohexandicarboxylic acid 1,3-cyclohexandicarboxylic acid, diglycolic acid, itaconic acid, maleic acid, brasilic acid, and acid 2,5-norbornandicarboxylic.

As derivatives that form acid esters aliphatic or cycloaliphatic dicarboxylic acids named above, which they are also usable, esters can be named in particular of C 1 to C 6 dialkyl, such as dimethyl, diethyl ester, di-n-propyl, di-isopropyl, di-n-butyl, di-iso-butyl, di-t-butyl, di-n-pentyl, di-iso-pentyl or di-n-hexyl. They can also anhydrides of dicarboxylic acids are used.

In such cases the acids can be used dicarboxylic or their derivatives that form esters, individually or as a mixture of two or more thereof.

It is preferred to use succinic acid, adipic acid, azelaic acid, sebacic acid, brasilic acid or their respective derivatives that form esters or mixtures thereof. Particularly it is preferred to use succinic acid, adipic acid or sebacic acid or its respective derivatives that form esters or mixtures thereof. Particularly preferred is adipic acid or their derivatives that form esters, such as their alkyl esters or their mixtures As aliphatic dicarboxylic acids are used preferably sebacic acid or mixtures of sebacid acid with acid adipic, if polymer blends are produced with components ii) "hard" or "brittle", such as polyhydroxybutyrate or particularly polylactide. As acid aliphatic dicarboxylic acid is preferably used succinic acid or mixtures of succinic acid with adipic acid, if mixtures occur polymeric components ii) "soft" or "viscous", such as polyhydroxybutyrate vetolate.

Succinic acid, azelaic acid, sebacic acid and Brazilian acid also have the advantage that they are accessible as renewable raw materials.

As aromatic dicarboxylic acid a2 can be named in general those with 8 to 12 carbon atoms and preferably those with 8 carbon atoms. For example, Terephthalic acid, isophthalic acid, acid may be mentioned. 2,6-naphthoic and 1,5-naphthoic acid as well as derivatives thereof that form esters. In that case the dialkyl esters of C 1 -C 6, for example dimethyl ester, of diethyl, di-n-propyl, of di-iso-propyl, of di-n-butyl, of di-iso-butyl, of di-t-butyl, of di-n-pentyl, of di-iso-pentyl or of di-n-hexyl. The anhydrides of A2 dicarboxylic acids are also ester forming derivatives adequate. Although in principle acids can also be used a2 aromatic dicarboxylic acids with a greater number of atoms of carbon, for example up to 20 carbon atoms.

Aromatic dicarboxylic acids or their a2 ester forming derivatives can be used individually or as a mixture of two or more thereof. Particularly preferred terephthalic acid or its ester-forming derivatives, such as dimethyl terephthalate.

As a compound containing sulfonate groups usually an alkali metal salt is used or alkaline earth of a dicarboxylic acid that contains sulfonate groups or their ester forming derivatives, of preferred way alkali metal salts of the acid 5-sulfoisophthalic or mixtures thereof, particularly preferable sodium salt.

According to one of the preferred forms of embodiment the acid component A contains from 40 to 60 mol% of a1, from 40 to 60% molar of a2 and from 0 to 2% molar of a3. According another preferred embodiment the acid component A contains from 40 to 59.9% molar of a1, from 40 to 59.9% molar of a2 and of 0.1 to 1 mole% of A3, especially 40 to 59.8 mole percent of A1, from 40 to 59.8 mol% of a2 and from 0.2 to 0.5 mol% of a3.

In general, B-diols are selected from branched or linear alkanols with 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, or cycloalkandiols with 5 Up to 10 carbon atoms.

Examples of suitable alkanols are ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentandiol, 2,4-dimethyl-2-ethylhexan-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 2,2,4-trimethyl-1,6-hexanediol, especially ethylene glycol, 1,3-propanediol, 1,4-butanediol and 2,2-dimethyl-1,3-propanediol (neopentyl glycol); cyclopentandiol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol or 2,2,4,4-tetramethyl-1,3-cyclobutandiol. Particularly preferred are 1,4-butanediol, in particularly in combination with adipic acid as component a1) and 1,3-propanediol, especially in combination with sebacic acid as component a1). 1,3- Propandiol also has the advantage that it is accessible as renewable raw material. Can also be used mixtures of various alkanols.

Depending on whether an excess of groups is desired acids or OH, component A may be used in excess or component B. According to a preferred embodiment the molar relationship between components A and B can be found in the range from 0.4: 1 to 1.5: 1, preferable in the range of 0.6: 1 to 1.1: 1.

Together with components A and B, polyesters on which the polyester blends of the invention are based They may contain other components.

As dihydroxy compounds c1 is used of preferred way diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol and polytetrahydrofuran (poly-THF), particularly preferable diethylene glycol, triethylene glycol and polyethylene glycol, and also the mixtures thereof or compounds that have different variables n (see formula I), for example polyethylene glycol, which contains propylene units (n = 3), which can be obtained, for example, by polymerization according to methods known per se of, first, ethylene oxide and then with oxide of propylene, particularly preferably a polymer based on polyethylene glycol, with various variables n, and predominate units formed from ethylene oxide. Molecular weight (Mn) of polyethylene glycol is regularly selected in the range of 250 to 8000, preferably 600 to 3000 g / mol.

According to one of the preferred forms of embodiment, for the production of polyesters partially aromatics can be used, for example, from 15 to 98, preferably from 60 to 99.5 mole% of diols B and 0.2 to 85, preferably 0.5 up to 30 molar% of the dihydroxy compounds c1, referred to the molar amount of B and c1.

In a preferred embodiment, such as hydroxycarboxylic acid c2) is used: glycolic acid, D-, L-, D, L-lactic acid 6-hydroxyhexanoic, its cyclic derivatives as glycolide (1,4-dioxan-2,5-dione), D-, L-dilactide (3,6-dimethyl-1,4-dioxan-2,5-dione), p-hydroxybenzoic acid as well as its oligomers and polymers such as 3-polyhydroxybutyric acid, acid polyhydroxyvaleric, polylactide (obtainable, for example, as NatureWorks® 4042D (company NatureWorks)) and a mixture of acid 3-polyhydroxybutyric acid polyhydroxy-valeric (obtainable from PHB companies Industrial, Tianan or Metabolix), for the preparation of polyesters Particularly aromatic derivatives are particularly preferred cyclic and low molecular weight thereof.

Hydroxycarboxylic acids can be used in amounts of, for example, 0.01 to 50, preferably 0.1 to 40% by weight based on the amount of A and B.

How alkanol (C 2 -C 12) amine or cycloalcanol (C 5 -C 10) amine (Component c3), and among these must also fit methylcyclohexanemethanol-4-amine, se preferably use alkanol (C 2 -C 6) amines as ethanol-2-amine, propanol-3-amine, butanol-4-amine, pentanol-5-amine, hexanol-6-amine and cycloalcanol (C 5 -C 6) amines as cyclopentanolamine and cyclohexanelamine or mixtures of the same.

How (C 1 -C 8) alkane - diamine (component c4) are preferably used (C4-C6) alkane - diamines like 1,4-butanediamine, 1,5-pentanediamine and 1,6-hexanediamine (hexamethylenediamine, "HMD").

According to a preferred embodiment, for the production of partially aromatic polyesters can used from 0.5 to 99.5 mol%, preferably from 0.5 to 50 mol%, of c3, referring to the molar amount of B, and from 0 to 50, preferably from 0 to 35% molar, of c4, based on the molar amount of B.

The 2,2'-bisoxazolines c5 of the general formula III in general can be obtained by the method of Angew. Chem. Int. Edit., Vol. 11 (1972), pages 287-288. Particularly preferred bisoxazolines are those in which R1 means a single link, a group alkylene (CH 2) z, with z = 2, 3 or 4 as methylene, ethan-1,2-diyl, propan-1,3-diyl, propan-1,2-diyl, or a group phenylene As particularly preferred bisoxazolines, they can to mention 2,2'-bis (2-oxazoline), bis (2-oxazolinyl) methane, 1,2-bis (2-oxazolinyl) ethane, 1,3-bis (2-oxazolinyl) propane or 1,4-bis (2-oxazolinyl) butane, especially 1,4-bis (2-oxazolinyl) benzene, 1,2-bis (2-oxazolinyl) benzene or 1,3-bis (2-oxazolinyl) benzene.

For the production of polyesters partially aromatic can be used, for example, from 70 to 98% molar of B, up to 30% molar of c3 and 0.5 up to 30% molar of c4 and 0.5 up to 30% molar of c5, respectively referred to the sum of the molar amounts of components B, c3, c4 and c5.

According to another preferred embodiment it is possible to use from 0.1 to 5, preferably from 0.2 to 4% by weight of c5, referring to the total weight of A and B.

As component c6 acids can be used natural aminocarboxylic acids These include valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, lysine, alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, proline, serine, triosine, asparagine or glutamine

Preferred aminocarboxylic acids of the general formulas IVa and IVb are those where s means a integer 1 to 1000 and t means an integer from 1 to 4, preferably 1 or 2 and T is selected from the phenylene group and - (CH 2) u -, where u means 1, 5 or 12.

In addition, c6 can also be a polyoxazoline of the general formula V. But c6 can also be a mixture of different aminocarboxylic acids and / or polyoxazolines.

According to a preferred embodiment c6 it can also be used in amounts of 0.01 to 50, preferable from 0.1 to 40% by weight, based on the total amount of components A and B.

As additional components that can optionally used for the production of polyesters partially flavored d1 compounds containing at least three groups capable of forming esters.

Compounds d1 preferably contain three up to ten functional groups that are capable of forming bonds of ester. Particularly, preferred compounds d1 have three to six such functional groups in the molecule, especially three to six hydroxyl groups and / or carboxyl groups.

As an example they can be named: acid tartaric, citric acid, malic acid; trimethylolpropane, trimethylolethane; pentaerythritol; polyether triols; glycerin; acid quarterly; trimellitic acid, trimellitic acid anhydride, trimellitic anhydride; pyromellitic acid, pyromellitic dianhydride and hydroxyisophthalic acid.

D1 compounds are regularly used in amounts from 0.01 to 15, preferably 0.05 to 10, particularly preferably 0.1 to 4% molar, based on component A.

As component d2 one or a mixture of various isocyanates. Aromatic diisocyanates or aliphatic But functionality isocyanates can also be used higher.

For an aromatic diisocyanate d2 in the context of the present invention are understood above all Toluylene-2,4-diisocyanate, Toluylene-2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthylene-1,5-diisocyanate or xylethylene diisocyanate. For example, the isocyanates available under the name Basonat® of the company BASF Aktiengesellschaft.

Among these, 2,2'- are particularly preferred, 2,4'- and 4,4'-diphenylmethane diisocyanates as component d2. In general, the latest diisocyanates are used as mixture.

As d2 three-core isocyanate it is also take into consideration tri (4-isocyanophenyl) methane. The Multi-core aromatic diisocyanates are produced, for example, for example during the preparation of diisocyanates of one or two cores

In lower amounts of, for example, up to 5% by weight based on the total weight of the d2 components, the component d2 may also contain urethione groups, to cover Isocyanate groups.

For an aliphatic diisocyanate d2 in the context of the present invention are understood above all linear or branched alkylenedisocyanates or cycloalkylene diisocyanates with 2 to 20 carbon atoms, preferably 3 to 12 carbon atoms, for example 1,6-hexamethylene diisocyanate, isophorondiisocyanate or methylene bis (4-isocyanoccyclohexane). Particularly preferred d2 aliphatic diisocyanates are 1,6-hexamethylene diisocyanate e isoforondiisocyanate.

Preferred isocyanurates include the aliphatic isocyanurates that are derived from alkylene diisocyanates or cycloalkylene diisocyanates with 2 to 20 carbon atoms, preferably 3 to 12 carbon atoms, for example isophorondiisocyanate or methylene bis (4-isocyanoccyclohexane). In this case the alkylenediisocyanates can be both linear as branched. Particularly preferred are isocyanurates that are based on n-hexamethylene diisocyanate such as, by example, cyclic trimers, pentamers or higher oligomers of the n-hexamethylene diisocyanate.

In general, component d2 is used in amounts of 0.01 to 5, preferably 0.05 to 4 molar%, particularly preferably 0.1 to 4 molar% referred to the sum of the molar amounts of A and B.

As divinyl ether d3 in general can be used all usual and commercially obtainable divinyl ethers. Preferably they are used: 1,4-butanediol divinyl ether, 1,6-hexandiol divinyl ether or 1,4-cyclohexandimetanoldivinyl ether or mixtures of same.

Preferably divinyl ethers are used. in amounts of 0.01 to 5, especially 0.2 to 4% by weight, referred to the total amount of A and B.

Examples of partially aromatic polyesters Preferred are based on the following components

A, B, d1

A, B, d2

A, B, d1, d2

A, B, d3

A, B, c1

A, B, c1, d3

A, B, c3, c4

A, B, c3, c4, c5

A, B, d1, c3, c5

A, B, c3, d3

A, B, c3, d1

A, B, c1, c3, d3

A, B, c2.

Among these, particularly preferred partially aromatic polyesters based on A, B, d1 or A, B, d2 or in A, B, d1, d2. According to another preferred embodiment the polyesters partially aromatic are based on A, B, c3, c4, c5 or A, B, d1, c3, c5.

Partially aromatic polyesters mentioned and mixtures of polyesters according to the invention They are regularly biodegradable.

In the sense of the present invention the "biodegradable" property for a substance or mixture of substances is met when this substance or substance mixture presents a percentage degree of biological decomposition of at minus 60% in at least one of the three methods defined in DIN V 54900-2 (pre-standard, status September 1998).

In general, biodegradability leads to polyester (mixtures) decomposing in a convenient and verifiable period of time. The decomposition can be carried out enzymatically, hydrolytically, oxidatively and / or by the action of electromagnetic radiation, for example UV radiation, and in most cases it occurs in a preponderant part, by the action of microorganisms such as bacteria, yeasts, fungi and algae. Biodegradability can be quantified, for example, by mixing the polyester with compost and leaving it stored for a certain time. For example, according to DIN EN 13432 or DIN V 54900-2, method 3, an air stream devoid of CO2 is passed through compost matured during the composting process and this is subjected to a defined temperature program . In this way the biodegradability is defined by the relationship between the net release of CO2 from the sample (after extraction of the release of CO2 by the compost without sample) and the maximum release of CO2 of the sample (calculated from the carbon content of the sample) as a percentage degree of biological decomposition. Biodegradable polyesters (blends) regularly show clear signs of decomposition after a few days of composting, such as fungal growth, cracking and cracking.
holes

Other methods for determining Biodegradability is described, for example, in ASTM D 5338 and ASTM D 6400

The preparation of the polyesters partially flavored is known per se or can be done according to methods known per se.

Partially aromatic polyesters Preferred are characterized by a molecular weight (Mn) in the range of 1000 to 100,000, in particular in the range of 9,000 to 75,000 g / mol, preferable in the range of 10,000 to 50,000 g / mol and one point of fusion in the range of 60 to 170, preferable in the range of 80 up to 150 ° C.

Partially aromatic polyesters mentioned can present hydroxyl and / or carboxyl groups in any proportion Partially aromatic polyesters These can also be modified in their extreme groups. So can be modified acidically, for example, extreme groups OH by reaction with phthalic acid, phthalic acid anhydride, trimellitic acid, trimellitic acid anhydride, acid pyromellitic or pyromellitic acid anhydride.

As components ii of the mixtures of biodegradable polyesters polylactide is preferred with the following properties profile:

?

a rat melting volume (MVR at 190 ° C and 2.16 kg according to ISO 1133 of 0.5 - preferably 2 - up to 9 ml / 10 minutes

?

a melting point below 175 ° C;

?

a glass point (Tg) greater than 55 ° C

?

a water content less than 1000 ppm

?

a residual content of monomers (L-lactide) less than 0.3%.

?

a molecular weight greater than 80 000 Dalton.

Preferred component ii is, for example, NatureWorks® 4020 or 4042D (company polylactide NatureWorks).

As component iii a copolymer is suitable containing epoxy groups based on styrene, acrylates and / or methacrylates The units that have epoxy groups are preferably glycidyl (meth) acrylates. Have shown copolymers with a fraction of glycidyl methacrylate greater than 20, particularly preferably greater than 30 and particularly preferably greater than 50% by weight of the copolymer, as marketed, for example, by the Johnson company Polymer under the brand Joncril® ADR 4368. The average molecular weight of the polymers is preferably 2000 to 20,000, in particular 4000 to 12,000.

By nucleation agents iv) are understood as example, talc, chalk, huma black, graphite, calcium stearate or zinc, poly-D-lactic acid, N, N'ethylene-bis-12-hydroxystearamide or polyglycolic acid.

These auxiliary substances are used in a concentration of 0.5 to 3% by weight based on the total weight of the components i) and ii).

The addition of nucleating agents is particularly advantageous and has a positive effect on the preparation of foam layers. The finely nucleating agent dispersed represents a surface for cell formation thanks to which a homogeneous structure of cells is achieved and It can have an influence on foam density.

Biodegradable polyester blends according to the invention usually contains from 5 to 70% by weight, preferable from 10 to 50% by weight, particularly preferably from 10 to 30% by weight of component i and 30 to 95% by weight, preferably 50 up to 90% by weight, particularly preferably from 70 to 90% in weight of component ii, and weight percentages refer to weight total components i up to ii and together result in 100% in weigh.

Component iii) is used in 0.1 to 5% in weight, preferably 0.1 to 2% by weight, and particularly preferable in 0.2 to 1% by weight, based on the total weight of the components i) to ii).

Preparation of polyester blends biodegradable according to the invention is made from the individual components according to known methods (EP 792 309 and US 5,883,199).

For example, all components i, ii and iii they are mixed in one step of the process in devices known for the person versed in the subject, for example kneaders or extruders to high temperatures, for example from 120 ° C to 250 ° C, and are made react. The reaction is preferably carried out in the presence of a radical initiator.

In addition, the process described in WO 2006/07815 for the production of polyester blends biodegradable

For this, it is mixed in a first step 1 until 50% by weight, preferably 5-35% by weight of component iii with 50 to 99% by weight and preferably 65 to 95% by weight of component i at temperatures of 110 to 145 ° C - preferably 120 up to 140 ° C - to produce a parallel batch. At these temperatures a homogeneous mixture is obtained without increasing significant molecular weight. The parallel batch thus obtained It can be stored without problem at room temperature. In a second step by adding the batch parallel to the component ii and optionally other components i the composition is adjusted desired. This composition formation step is performed at 150 up to 250 ° C - preferably at 160 to 190 ° C.

For the production of extrusion foams the components are mixed in an extruder with one or two screws endless at 160 to 220 ° C. At these temperatures you get a homogeneous mixture. Preferably PLA (component ii) is formed a continuous or co-continuous phase.

The records of scanning electroscopy and transmission show that when using a twin screw extruder without finally, a discontinuous phase composed of domains of component i with a diameter less than 150 nm. This way it they achieve cell walls with diameters smaller than 200 nm in which The discontinuous phase is still dispersed in the matrix. This way you Prevents a rupture of the cells during the expansion operation. This in turn leads to higher fractions of larger closed cells. 70%, particularly over 80% and particularly preferable over 90%. Low cell wall thicknesses less than 200 nm also lead to densities less than 50 g / l and preferably under 30 g / l.

The fusion is incorporated 1-25% by weight, preferably 1-15% by weight, of agent propellant Physical propellant agents are used to ensure low foam density Examples of suitable propellants are linear alkanes preferably with 4-6 atoms of carbon, nitrogen, carbon dioxide, ethanol, dimethyl ether, diethyl ether, methyl ethyl ether, as well as combinations of same. Particularly preferred are butane, pentane, nitrogen and carbon dioxide, in particular carbon dioxide. The merger is then cools in a twin screw extruder. By way of alternate, the cooling can be performed in a back segment of the single screw worm fusion extruder. At selected temperatures should pay attention to the pressure in the extruder is high enough to prevent a potential early foam formation in the extruder. If a nozzle is used of holes you get foam cords that have a surface smooth, shiny.

Alternatively, for this purpose you can an annular geometry be used for the nozzle in order to obtain foam layers in the form of hoses or flexible tubes. Layers Extruded flexible tube-shaped foam is cooled with air, for example, they are cut with a knife and smooth foam layers that arise in this way are rolled on a roller. In this case Care must be taken to roll it with a constant speed. The winding speed can influence the foam density In addition, during extrusion and curl should be careful that foam films have a homogeneous thickness distribution, since this is decisive importance for the process of thermoforming that follows.

Extruded layers of foam can be heated in a thermoforming apparatus by uniform heating and short time, for example with a source of infrared heat at 80-120 ° C, particularly preferable 90-100 ° C and heat molded in a mold to reach a defined shape of a layer of foam by vacuum, optionally using compressed air and at then cool with air, for example.

A particular field of application of mixtures of biodegradable polyesters with low oil and water absorption refers to the use for the production of foam layers, for representation of foamed gaskets, such as thermoformed gaskets for food

Examples Industrial application measurements

The absorption of oil, water and ethanol is determined as follows:

The defined foam laces of equal diameter were welded at the ends, weighed and stored for several hours at room temperature or at 60 ° C in oil or water. The relative weight gain of the cord was determined. The weight molecular Mn of partially flavored polyesters are determined as follows:

15 mg of the polyesters partially flavored were dissolved in 10 ml of hexafluoroisopropanol (HFIP). 125 µl of this solution was analyzed by gel permeation chromatography (GPC). The measurements are They performed at room temperature. For elution HFIP + was used 0.05% by weight of potassium salt of trifluoroacetic acid. The elution rate was 0.5 ml / min. In this case the next combination of columns (all columns produced by Showa Denko Ltd., Japan): Shodex® HFIP-800P (diameter 8 mm, length 5 cm), Shodex® HFIP-803 (diameter 8 mm, length 30 cm), Shodex® HFIP-803 (diameter 8 mm, length 30 cm). The partially aromatic polyesters were detected by means of a RI detector (differential refractometry). The calibration was performed with closely distributed polymethylmethacrylate standards with molecular weights of Mn = 505 to Mn = 2,740,000. Sectors of elution that were found outside this range were determined by extrapolation.

The melting temperatures of polyesters partially flavored were determined by DSC measurements with an Exstet DSC 6200R device from Seiko:

10 to 15 mg of the respective samples are heated under a nitrogen atmosphere with a speed of heating of 20 ° C / min from -70 ° C to 200 ° C. As temperatures of sample melting peak peak temperatures were indicated of fusion observed in this case. A crucible was used as a reference of empty samples.

The homogeneity of mixtures of components i, ii, and iii as well as mixtures prepared for comparison was determined by pressing these mixtures at 190 ° C respectively to sheets with a thickness of 30 µm. The fraction of components ii present in a non-dispersed manner in these sheets are assessed by eye inspection measure.

From polyester blends biodegradable foam layers were prepared respectively with a thickness of 2 to 3 mm by means of extrusion and use of a nozzle cancel.

Density was determined by weighing the sample of foam and determining the volume of displacement in water.

To determine the fraction of closed cells a cross section of the foam cord or layer was analyzed of foam by means of electron microscopy. In a section quadrangular was determined the fraction of those cells that It contains a closed cell wall structure.

The cell wall fortress and morphology were determined by transmission microscopy of electrons and electron scanning microscopy.

Application substances Component i

i-1: For the production of polyester i-1 mixed 87.3 kg of terephthalate dimethyl, 80.3 kg of adipic acid, 117 kg of 1,4-butanediol and 0.2 kg of glycerin together with 0.028 kg of tetrabutylortotitanate (TBOT), and the molar ratio between Alcohol components and the acid component was 1.30. Mix of reaction was heated to a reaction temperature of 180 ° C and at This temperature was transformed for 6 hours. Then you raised the temperature to 240 ° C and excessive dihydroxy compound it was distilled under vacuum for a period of 3 h.

Then 0.9 kg of hexamethylene diisocyanate at 240 ° C within 1 h.

The i-1 polyester obtained from this way had a melting temperature of 119 ° C and a weight molecular (Mn) of 23000 g / mol (corresponds Ecoflex® FBX 7011, prepared by BASF Aktiengesellschaft).

Component ii

ii-1: aliphatic polyesters, Natureworks® 4042D polylactide from NatureWorks.

Component iii

iii-1: Joncril® ADR 4368 of the Johnson Polymer company.

Other components

Nucleating agents: talc, chalk.

A hole nozzle was used in each case to get laces.

Examples 1 to 4

5

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6

Example 2 shows that by using the compatibilizers the fraction of closed cells can increase further compared to example 1, of all Modes already very good.

Water absorption

7

Olive Oil Absorption

9

Ethanol absorption

10

Example 2 shows impressively that water and oil absorption can be drastically reduced by the compatibilizer according to the invention.

Claims (16)

1. Foam layer based on a mixture of biodegradable polyester comprising

i)

70 to 5% by weight, based on the total weight of the components i) to ii), of at least one acid-based polyester aliphatic and aromatic dicarboxylic and dihydroxy compound aliphatic and

ii)

30 to 95% by weight, based on the total weight of the components i) to ii), of polylactide, and

iii)

0.1 to 5% by weight, based on the total weight of the components i) to ii), of a copolymer, which contains groups epoxide, based on styrene, acrylates and / or methacrylates, Y

iv)

0.5 to 3% by weight, based on the total weight of the components i) to ii), of a nucleating agent, and

v)

0 to 50% by weight of inorganic filler material or organic

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2. Foam layer according to claim 1, in which component i) is structured of:

TO)

an acid component of

a1)

30 to 99 mol% of at least one acid aliphatic or at least cycloaliphatic dicarboxylic acid or its derivatives which form esters or mixtures thereof

a2)

1 to 70 mol% of at least one dicarboxylic acid aromatic or its ester forming derivative or mixtures thereof Y

a3)

0 to 5 mole% of a compound containing groups sulfonate;

quad

the molar percentages of components a1) up to a3) add 100% together and

B)

a diol component from at least one alkaliol from C 2 to C 12 or a C 5 cycloalkanediol up to C_ {10} or mixtures thereof and, if desired, also one or several components selected from

C)

a selected component of

c1)

at least one dihydroxy compound, which contains ether functions, of the formula I

(I) HO - [(CH 2) n -O] m -H

quad

in which n represents 2, 3 or 4 and m represents a integer from 2 to 250,

c2)

at least one hydroxycarboxylic acid of the formulas IIa or IIb

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eleven

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quad

in which p means an integer of 1 up to 1500 and r means an integer from 1 to 4, and G represents a residue that is selected from the group consisting of phenylene, - (CH 2) q -, where q means a number integer from 1 to 5, -C (R) H- and -C (R) HCH2, where R represents methyl or ethyl

c3)

at least one alkanol (C 2 -C 12) amine or al minus a cycloalcanol (C 5 -C 10) amine or mixtures thereof

c4)

at least one alkane (C 1 -C 8) diamine

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c5)

at least one 2,2'-bisoxazoline of the general formula III

12

quad

where R1 means a single bond, a group (CH 2) z alkylene, with z = 2, 3 or 4, or a group phenylene

c6)

at least one aminocarboxylic acid selected from group consisting of natural amino acids, polyamides, obtainable by polycondensation of a dicarboxylic acid with 4 to 6 C atoms and a diamine with 4 to 10 C atoms, composed of formulas IVa and IVb

13

quad

where s means an integer from 1 to 1500 and t means an integer from 1 to 4, and T represents a residue selected from the group consisting of phenylene, - (CH 2) u -, where u means an integer of 1 up to 12, -C (R2) H- and -C (R 2) HCH 2, where R 2 represents methyl or ethyl, and polyoxazolines with the periodic unit V

14

quad

in which R 3 represents hydrogen, alkyl of C 1 -C 6, cycloalkyl of C 5 -C 8, unsubstituted or substituted phenyl up to three times with alkyl groups of C 1 -C 4 or represents tetrahydrofuryl, or mixtures of c1) to c6)

quad

Y

D)

a selected component of

d1)

at least one compound with at least three groups capable of forming esters,

d2)

at least one isocyanate

d3)

at least one divinyl ether or mixtures of d1) up to d3).

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3. Foam layer according to claim 2, where in component i):

?

aliphatic dicarboxylic acid or cycloaliphatic (component a1)) means succinic acid, acid adipic or sebacic acid, its derivatives that form esters or mixtures thereof;

?

aromatic dicarboxylic acid (component a2)) means terephthalic acid or its derivatives that they form esters,

Y

?

the diol component (component B) means 1,4-butanediol or 1,3-propanediol.

4. Foam layer according to claims 1 up to 3, where component ii) is a polylactide with a rat of melting volume (MVR at 190 ° C and 2.16 kg according to ISO 1133) from 2 to 9 ml / 10 minutes. 5. Foam layer according to claims 1 up to 4, where component iii) has an epoxide fraction greater than 30% 6. Foam layer according to claims 1 up to 5 with a density less than 50 g / l. 7. Foam layer according to claims 1 up to 6 with a fraction of closed cells greater than 70%. 8. Foam layer according to claims 1 up to 7 with a maximum water absorption at 23ºC and 4 hours less 10% by weight. 9. Foam layer according to claims 1 up to 6 comprising 10 to 30% by weight of component i) and 70 up to 90% by weight of component ii), respectively referred to total weight of components i) to ii). 10. Foam layer according to claim 1, where component ii) forms a continuous or co-continuous phase. 11. Foam layer according to claims 1 up to 10 with a layer thickness of 0.5 to 100 cm. 12. Foam layer according to claims 1 up to 11 comprising 0.1 to 2% by weight of component iii), referred to the total weight of the components i) to ii). 13. Foam layer according to claims 1 up to 12, containing as load material v) 5 up to 50% in weight referred to components i) and ii) of a polymer renewable. 14. Method for the production of a foam layer according to claims 1 to 13, characterized in that

to)

Mix in the extruder at 160 to 220 ° C a biodegradable polyester blend comprising

i)

70 to 5% by weight, based on the total weight of the components i) to ii), of at least one acid-based polyester aliphatic and aromatic dicarboxylic and dihydroxy compound aliphatic and

ii)

30 to 95% by weight, based on the total weight of the components i) to ii), of polylactide, and

iii)

0.1 to 5% by weight, based on the total weight of the components i) to ii), of a copolymer, which contains groups epoxide, based on styrene, acrylates and / or methacrylates, Y

iv)

0.5 to 3% by weight, based on the total weight of the components i) to ii), of a nucleating agent, and

v)

0 to 50% by weight of inorganic filler material or organic;

b)

1 to 25% by weight of a gas is injected pressurized physical propellant agent and

C)

it cools and is extruded in a layer of foam and optionally it is thermoformed in an apparatus of thermoforming

15. Method according to claim 14, wherein It uses carbon dioxide as a propellant. 16. Use of the foam layer according to claims 1 to 13 for heat and sound insulation.